var arr=[1,2,3,4,5,6,7];

var arr1=["你好","世界"];

console.log(arr.concat(arr1));
//返回：[1, 2, 3, 4, 5, 6, 7, "你好", "世界"]

var arr2=["我","你","她","他"];
console.log(arr2.join("爱"));
//返回：我爱你爱她

